Process for lining a channel and fitting and withdrawal slide for implementing it

ABSTRACT

A method of lining a sewer in which an inner pipe is introduced into an  eting sewer, and the space between the outer surface of the inner pipe and the inner surface of the sewer is filled with a filler. To introduce the filler into the space, at least one supply duct which preferably is provided with a delivery nozzle is introduced into the sewer until the at least one supply duct extends over the entire longitudinal length of the inner pipe. Subsequently, the at least one supply duct is removed by a withdrawal movement. During the removal of the at least one supply duct, the filler is delivered into the space through the duct or through the delivery nozzle preferably provided on the duct in an amount sufficient to completely fill the space. An introduction and removal slide for carrying out the method comprises two skids interconnected by a web and a fixing means for fixing the at least one supply duct, by means of which the duct is fixable at approximately equal distances from the skids and substantially parallel thereto.

The invention relates to a method of lining a sewer, which methodcomprises introducing an inner pipe lining pipe, liner, or reliner, intoan already existing and possibly damaged sewer, and filling the annularspace between the outer surface of the inner pipe and the inner surfaceof the sewer with filler. The invention also relates to an introductionand removal slide usable in implementing this method.

The renovation of damaged, mostly old, sewer pipes of inaccessiblecross-section has become a grave concern for operators of sewage pipenetworks and increasingly requires ever rising financial and personalexpenditures. The substantial lengths of old sewer and drainage ducts,respectively, which are already damaged or which are expected to becomedamaged shortly pose problems both in terms of drainage technology(cloggings, road cave-ins, etc.) and in terms of environmentaltechnology, because groundwater gets contaminated by emerging wastewater. Because of narrow routes and high traffic density, in most casesonly underground modes of construction are feasible for the renewal ofducts already present, and the following requirements must be met: no oronly little groundwork short construction times, minimal interruptionsof the operation of the network, maintenance or improvement of theexisting hydraulic conditions and low costs as compared to a newconstruction carried out in open construction manner.

Among the renovation methods, those methods become increasinglyimportant which re-line the existing, damaged sewer by introducing a newinner pipe into the sewer and filling the annular space remainingbetween the outer surface of the inner pipe and the inner surface of thesewer with filler. However, particularly if paths of more than tenmeters are to be filled, filling of the annular space proves to bedifficult. Hitherto, filler has been pushed under pressure into theannular space from one side or flushed in without pressure. Completefilling of the annular space can hardly be guaranteed, and cannot bechecked, either.

Departing from this, it is the object of the present invention toprovide a method of the initially mentioned type which is distinguishedby an easier handling, a complete and checkable filling of the annularspace, a large choice of fillers available and shorter filling timesrequired.

The method according to the invention of the initially mentioned type ischaracterized in that for introducing filler into the said annularspace, at least one supply duct which is preferably provided with adelivery nozzle is introduced into this annular space until this atleast one supply duct extends over the entire length of the inner pipe,and that subsequently this at least one supply duct is removed by areturn movement and during removal of this at least one supply ductfiller in an amount sufficient or completely filling the annular spaceis delivered into the annular space through this at least one supplyduct or through the nozzle provided on this at least one supply duct. Bythis design the above-indicated object can be met well.

As regards the organization of construction sites and the procedure, asuitable embodiment of the method according to the invention ischaracterized in that at least one supply duct is introduced into theannular space, starting at one end of the inner pipe and extending tothe other end of the inner pipe.

Another embodiment of the method according to the invention with whichgreat lengths of the respective sewer sections to be lined can betreated is characterized in that at least one supply duct is introducedfrom each end of the inner pipe as far as to a site located in themiddle region of the longitudinal extension of the inner pipe and fromthere is returned to its site of introduction.

For introducing the supply duct utilized in the method according to theinvention into the sewer, an advantageous embodiment of this methodprovides for introducing the supply duct to be arranged in the annularspace at the outer surface of the inner pipe into the sewer togetherwith the inner pipe. An embodiment of the method according to theinvention similarly suitable in terms of introducing the supply duct, inwhich the introduction of the inner pipe is simpler than in thepreviously mentioned embodiment insofar as no attention need be paid tothe supply duct when the inner pipe is being introduced into the seweris characterized in that together with the inner pipe, an auxiliary ropeis introduced at the outer surface of the inner pipe into the annularspace formed in the sewer, whereupon the supply duct is introduced withthe auxiliary rope into the annular space. As regards the introductionof the supply duct, a further suitable embodiment of the methodaccording to the invention is characterized in that a guide rope istensioned along the internal surface of the sewer, and the supply ductsare introduced and removed along the guide rope by suspension meansdisplaceable on the guide rope.

To achieve as stable a mounting as possible of the inner pipe in thesewer to be lined it is advantageous if the inner pipe is arranged onthe bottom of the sewer to be lined, and according to an embodimentwhich has proved particularly suitable in practice, the inner pipe isforced towards the bottom of the sewer in a manner known per se by meansof gravity, by filling the inner pipe with water, the annular space thusbeing sickle-shaped as viewed in cross-section.

As regards the flow of filler into the annular space present betweensewer wall and inner pipe it is advantageous if the supply duct andparticularly the delivery nozzle, during introduction and particularlyduring the removal thereof, is guided precisely above the inner pipe andas high as possible in the annular space.

To ensure uniform and complete filling of the annular space with fillerit is advantageous if the return speed and/or the material pressure inthe supply duct are continuously re-adjusted in accordance with thefiller used and the volume of the annular space by aid of a controlmeans arranged on the supply duct, in particular in the vicinity of thedelivery nozzle and communicating the filling degree of the annularspace so as to ensure complete filling of the annular space. Acomparatively simple design of the control means is obtained if a TVcamera is used as said control means. A variant thereto is characterizedin that at least one sensor, e.g. a humidity sensor, responding to thepresence and/or absence of filler is used as said control means.

To obtain a rapid procedure when filling the annular space between theinner surface of the sewer and the inner pipe it is advantageous if thesupply duct is designed in the form of two hoses and if a two componentmaterial forcibly mixed immediately upstream of the delivery nozzle isused as the filler. In this manner, a two component material can be usedwhich cures rapidly without causing problems when forced pauses occur,since the material components are brought into contact with each other,and thus caused to react, immediately just before the material flows outinto the annular space. With such two-component materials also a highdegree of expansion and a high strength can be achieved. Very goodpractical properties of the annular space filling can be obtained if, assaid filler, a statically strong, water-displacing, moisture-curing,non-ageing, chemical-resistant and environmentally harmlesstwo-component PU foam is used.

A very stable neutral filling of the annular space which also has a highstrength can be achieved if a lightweight concrete is used as saidfiller. A particularly favorable filling behavior which surely precludesthe formation of air-filled pockets is achieved if a grout made up ofwater and air concrete granules is used as said filling material.

In terms of apparatus, a very simple introduction of the filler forfilling the annular space can be achieved if a one-component PU foam ora late-reacting two-component PU foam already mixed before entering intothe supply duct is used as said filler.

A suitable procedure both in terms of introducing the supply duct intothe sewer and in terms of filling the annular space with filler can beachieved by an embodiment of the method which is characterized in thatthe introduction of the supply duct is effected downhill and the removalof the supply duct under simultaneous filling of the annular space iseffected uphill in the sense of the sewer ascent.

The introduction and removal slide provided within the scope of theinvention, which advantageously may be utilized for introducing andreturning the supply duct from the annular space present between theinterior surface of the sewer and the inner pipe, is characterized inthat the slide comprises two skids tightly interconnected by a web and afixing means for the supply duct by which the supply duct may be fixedat approximately equal distances from the skids and substantially inparallel to the same. Here, it is possible to obtain good positioningproperties within the sewer or within the annular space of the same, andthe slide is adaptable without any difficulty to various inner pipediameters by an appropriate design of the web, if it is provided for theweb to be designed such that after fixation of the web on the supplyduct, the distance between the skids is less the sum of the twodistances between the respective skid and the supply duct. A design ofthe skids of the slides as rearwardly and forwardly pointed, elongate,tubular bodies makes it possible to attain a very good stability of theslide with a simple construction, and a slide designed in this manner iseasy to produce. Such skids also sit well on the inner pipe and passsmall obstacles without any problems as the slide moves.

Slides of the above-mentioned type are very easy to fix to the supplyduct, e.g. by releasably attaching the web of the slide to the supplyduct. In doing so it is suitable if the slide is fixed to the supplyduct in the vicinity of the delivery nozzle.

The invention also relates to an introduction and removal arrangementcomprising several slides of the above-indicated design, and such anarrangement is characterized in that several equal slides are fixed tothe supply duct at pre-determined distances.

The invention will now be explained in more detail by way of examplesand with reference to the rough schematic drawing figures.

In the drawings,

FIGS. 1a and 1b illustrate two stages of an embodiment of the methodaccording to the invention.

FIG. 2 illustrates a mode of procedure when introducing the inner pipeand the supply duct into a sewer to be lined.

FIGS. 3a and 3b illustrate two stages when introducing the inner pipeand the supply duct according to another embodiment of the method of theinvention.

FIG. 4 illustrates a further mode of procedure when introducing thesupply duct into a sewer to be lined; the above-indicated figures arelongitudinal section representations.

FIGS. 5a and 5b show cross-sections of two stages when lining a seweraccording to a further embodiment of the method of the invention.

FIGS. 6a and 6b show a front view and a bottom view of an embodiment ofa slide provided within the scope of the invention.

FIG. 6c shows a variant of such a slide in a front view.

FIG. 7 shows another variant of such a slide, also in a front view.

FIG. 8 shows a sewer to be lined and already provided with an inner pipeinto which a slide as illustrated in FIG. 6c has been inserted, and

FIG. 9 shows a view of an embodiment of an introduction and removalmeans of the invention comprising several slides.

In rough schematic illustration, FIG. 1a shows a longitudinal section ofa sewer 1, equipped with manholes 2a, 2b leading to above ground, and tobe provided with a lining. To form this lining, in the stage illustratedin FIG. 1a, an inner pipe 3 has already been inserted into the sewer 1.A supply duct 5 has been inserted into the annular space 4 presentbetween the inner surface of the sewer 1 and the outer surface of theinner pipe 3, which supply duct has been advanced or pulled forward fromthe manhole 2a in the direction of arrow 5a and which is provided forintroducing a filler into the annular space 4. The supply duct 5schematically illustrated may comprise one or several pipes or hoses,depending on whether the filler 7 to be introduced into the annularspace through the duct 5 consists of one or several components. At itsexit end, the duct 5 is provided with a delivery nozzle 6. In thesubsequent stage illustrated in FIG. 1b, the duct 5 is then removedagain from the sewer 1 or from the annular space 4 formed in this sewer,by being withdrawn in the direction of arrow 5b. During this withdrawalmovement, filler 7 is delivered into this annular space in an amountsufficient to completely fill the annular space 4. The filler 7 is asolidifying mass which is sufficiently strong to stably support theinner pipe 3 in the sewer 1, and which also has good sealing properties.

FIG. 2 shows how the supply duct 5 for introducing filler into the sewer1 to be lined is introduced together with the inner pipe 3 introducedinto the sewer 1 for lining the same, according to one embodiment of themethod of the invention. This introduction is effected by moving forwardthe inner pipe 3 and the supply duct 5 in the direction of the arrow 5a,and for this common advance movement it is advantageous as a rule if thesupply duct 5 is releasably fixed to the inner pipe 3. As soon as theintroduction procedure has been finished, such a fixation is released,and subsequently the annular space present between the inner surface ofthe sewer 1 and the outer surface of the inner pipe 3 is filled withfiller analogously, as is shown in FIG. 1b.

With the embodiment of the method of the invention illustrated in FIGS.3a and 3b, an auxiliary rope 8 arranged at the outer surface of theinner pipe 3 is introduced into the sewer together with the inner pipe3, when the inner pipe 3 is introduced into the sewer to be lined, thisauxiliary rope passing through the annular space 4 formed between theinner pipe 3 and the inner surface of the sewer 1. In the subsequentphase, which is illustrated in FIG. 3b, the supply duct 5, as symbolizedby arrow 5a, is introduced into the annular space 4 with the auxiliaryrope 8 by pulling the latter outwards through the manhole 2b.

FIG. 4 illustrates a further technique of introducing the supply duct 5,wherein a guide rope 9 is tensioned along the inner surface of the sewer1, on which displaceable suspension means 14 are arranged to which thesupply duct 5 is then fixed. By the guide formed in this manner, thesupply duct 5 can be introduced easily and in a simple manner into theregion of the sewer 1 to be filled with filler, in the direction ofarrow 5a, and returned from this region in the direction of arrow 5b.

For a stable mounting of the inner pipe 3 in the sewer 1 and for fillingthe annular space 4 formed between the inner pipe 3 and the sewer 1 itis advantageous if the inner pipe is arranged towards the bottom of thesewer 1, as illustrated in more detail in FIGS. 5a and 5b, and thus anannular space 4 sickle-shaped in cross section results. In this case thesupply duct 5, as illustrated by FIG. 5a, is guided as high as possiblein the annular space 4 when it is introduced and particularly when it isremoved in which latter instance the filler is introduced into theannular space 4, and in this way the annular space 4 is completelyfilled with filler 7 in a very simple manner, as is illustrated by FIG.5b.

The embodiment of an introduction and removal slide illustrated in FIGS.6a and 6b comprises two skids 12a, 12b interconnected by a web 13. Thisweb 13 is formed by three struts 15, 16a, 16b, the struts 16a, 16bcarrying a fixing means 17 to which the supply duct 5 carrying adelivery nozzle 6 at its end can releasably be attached. The web 13 isdesigned such that the distance 18 between the skids 12a, 12b is smallerthan the sum of the two distances 19, 20 between the respective skid 12aor 12b, respectively, and the supply duct 5.

In the embodiment of an introduction and removal slide illustrated inFIG. 6c, the two skids 12a and 12b are interconnected via an angledstrut 13 carrying a holding shackle 21 in its middle by means of whichthe supply duct 5 can releasably be fastened to the slide.

With the embodiment of an introduction and removal slide illustrated inFIG. 7, whose construction is similar to the embodiment illustrated inFIG. 6c, a control means 10 is provided with which the introduction offiller into the sewer can be monitored, wherein such a control means,may, e.g., be formed by a small TV camera.

FIG. 8 shows a sewer 1 in cross-section, an inner pipe 3 beingintroduced in the sewer and a supply duct carried by a slide 12a, 12b,13, being guided in the annular space 4 between the inner pipe and theinner surface of the sewer 1 at the uppermost position. This guiding ofthe supply duct 5, i.e. of the delivery-side end thereof or of thedelivery nozzle 6 provided at the delivery-side end of the supply pipe,enables complete filling of the annular space 4 with filler in a simplemanner.

FIG. 9 illustrates an introduction and removal arrangement formed withseveral slides of the type illustrated in FIGS. 6a to 7, whichintroduction and removal arrangement is particularly advantageous ifgreater lengths of a supply duct 5 are to be guided. A number of slidesformed by skids 12a, 12b and webs 13 are arranged at mutual distancesand connected with the supply duct 5.

I claim:
 1. A method of lining a substantially horizontally extendingsewer comprising the steps of:introducing simultaneously an inner pipeand at least one supply duct removably fixed to a leading edge of theinner pipe into a sewer until the inner pipe is located completelywithin the sewer; and filling the space between the outer surface of theinner pipe and the inner surface of the sewer with a filler deliveredinto the space by means of the at least one supply duct leading into thespace; wherein the step of filling further comprises the stepsof:removing the at least one supply duct from its engagement with theinner pipe; removing the at least one supply duct by a withdrawingmovement; and delivering the filler into the space in an amountsufficient to completely fill the space during the withdrawing movementof the at least one supply duct.
 2. A method according to claim 1wherein the removing step further comprises withdrawing the at least onesupply duct above the inner pipe as high as possible in the space.
 3. Amethod according to claim 1 wherein at least one slide, having a pair ofelongate, tubular skids interconnected by a web is releasably attachedto said at least one supply duct and wherein the removing step furthercomprises using the at least one slide to guide the supply duct throughthe space in a fixed orientation with respect to the inner pipe.
 4. Amethod of lining a substantially horizontally extending sewer comprisingthe steps of:introducing an inner pipe into a sewer; and filling thespace between the outer surface of the inner pipe and the inner surfaceof the sewer with a filler delivered into the space by means of at leastone supply duct leading into the space; wherein the step of fillingfurther comprises the steps of:guiding the at least one supply duct intothe space by means of a guide so that the at least one supply ductextends over the entire longitudinal length of the inner pipe; removingthe at least one supply duct by a withdrawing movement; and during theremoval of the at least one supply duct, delivering the filler into thespace in an amount sufficient to completely fill the space wherein theguide for guiding the at least one supply duct into the space is anauxiliary rope adjacent the outer surface of the inner pipe which isintroduced into the space in the sewer together with the inner pipe, andwherein the at least one supply duct is subsequently guided into thespace by the auxiliary rope.
 5. A method of lining a substantiallyhorizontally extending sewer comprising the steps of:introducing aninner pipe into a sewer; and filling the space between the outer surfaceof the inner pipe and the inner surface of the sewer with a fillerdelivered into the space by means of at least one supply duct leadinginto the space; wherein the step of filling further comprises the stepsof:guiding the at least one supply duct into the space by means of aguide so that the at least one supply duct extends over the entirelongitudinal length of the inner pipe; removing the at least one supplyduct by a withdrawing movement; and during the removal of the at leastone supply duct, delivering the filler into the space in an amountsufficient to completely fill the space wherein the guide for guidingthe at least one supply duct into the space is a guide rope which istensioned along the inner surface of the sewer, and wherein the at leastone supply duct is suspended along the guide rope by at least onesuspension means which is displaceable on the guide rope.
 6. A methodaccording to claim 4 wherein the guiding step further comprises guidingthe at least one supply duct into the space starting at one end of theinner pipe and extending to the other end of the inner pipe.
 7. A methodaccording to claim 4 wherein the at least one supply duct comprises apair of supply ducts, and wherein the guiding step further comprisesguiding each supply duct into the space from an end of the inner pipe tothe middle of the inner pipe, and wherein the removing step furthercomprises withdrawing each supply duct from the space from the middle ofthe inner pipe to the respective end of the inner pipe.
 8. A methodaccording to claim 4 wherein the guiding step further comprises guidingthe at least one supply duct above the inner pipe as high as possible inthe space, and wherein the removing step further comprises withdrawingthe at least one supply duct above the inner pipe as high as possible inthe space.
 9. A method according to claim 4 wherein at least one slidecomprising a pair of elongate, tubular skids interconnected by a web isreleasably attached to said at least one supply duct, and wherein theguiding step further comprises using the at least one slide to guide theat least one supply duct into the space, and wherein the removing stepfurther comprises using the at least one slide to withdraw the at leastone supply duct from the space.
 10. A method according to claim 5wherein the guiding step further comprises guiding the at least onesupply duct into the space starting at one end of the inner pipe andextending to the other end of the inner pipe.
 11. A method according toclaim 5 wherein the at least one supply duct comprises a pair of supplyducts, and wherein the guiding step further comprises guiding eachsupply duct into the space from an end of the inner pipe to the middleof the inner pipe, and wherein the removing step further compriseswithdrawing each supply duct from the space from the middle of the innerpipe to the respective end of the inner pipe.
 12. A method according toclaim 5 wherein the guiding step further comprises guiding the at leastone supply duct above the inner pipe as high as possible in the space,and wherein the removing step further comprises withdrawing the at leastone supply duct above the inner pipe as high as possible in the space.13. A method according to claim 5 wherein at least one slide comprisinga pair of elongate, tubular skids interconnected by a web is releasablyattached to said at least one supply duct, and wherein the guiding stepfurther comprises using the at least one slide to guide the at least onesupply duct into the space, and wherein the removing step furthercomprises using the at least one slide to withdraw the at least onesupply dust from the space.